Frederick p



I No Drawing.

STATES PATENT. OFFICE.

FREDERICK I. WOOD, OF OAK PARK, ILLINOIS, ASSIGNOR TO AMERICAN CAN COMPANY,

, OF NEW YORK, N. Y., A CORPORATION OF NEWJEBSEY.

PROCESS OI PROOFING MATERIALS.

To all wh om z't may concern:

Be it known that I, FREDERICK P. Woon, a subject of the King of Great Britain, residin in Oak Park, in the county of Cook and tate of Illinois, have invented a new and ,useful Improvement in Processes of Proofing Materials, of which the following is a specification. v

This invention relates in general to the proofing of paper or fibrous materials and has more particular reference to the proofing of such articles in order that they may be used for the containing of fats, oils and the like.

My present invention has reference to the forming of a can or container body of the type and characteristics described in my pending application for containers filed March 5, 1915, Serial No. 12306.

In providing a paper or fibrous container adapted for the packaging of lard, lard substitutes and other greases and the like, I have found it advisable to coat the bodies of such containers with an infusible substance insoluble in theintended contents of the containers when in their most fluid condition. This proofing substance, to attain the bestresults, should be applied in the form of a continuous film over the body of the container. This invention has for its principal'object the provision of a process or method for the forming of such a film.

A further object of the invention is the provision of a method or process for coating articles of the character and in the manner described, which may be easily practised commercially and which will insure the production of containers of high and uniform quality.

Other objects and advantages of the invention will be apparent as it is more fully understood from the following description which is of a specific embodiment of it.

The coating may have varyin characteristics and be formed of materia s vof different qualities without departing from the spirit of the invention. I have found however in using a coating of the character described in my pending application, to

which reference has already been made, that if the material of the coating be permitted to penetrate the body of the container, considerable difficulty is experienced in the Specification of Letters Patent.

Patented J uly 22, 1919.

Application filed May 28, 1915. Serial No. 30,911.

formation of the continuous film desired and this by reason of the fact that the capillary action, which is present when the coating material is of su ciently low viscosity, causes the absorption of the film, which absorption however is not sufficient toprevent subsequent seeping out of the contents, the result of this absorption being merely a coating of the fibers of the container body as contradistinguished from a coating of the surface.

In accordance with my invention it is intended to control the fluidity of the bath in which the container bodies are immersed for coating at such a viscosity that this permeation will be reduced at least sufliciently to insure the formation of a coating upon thesurfaces desired to be protected.

This control of the fluidity I accomplish in the present instance by a control of the temperature of the bath in which the cans are immersed for coating. If hide glue be used as a proofing substance this temperature should be in the neighborhood of 110 F., for I have found that at or about that temperature it is best adapted to produce a surface film upon paper or other porous material. At that temperature also its ad hesive, qualities are well developed and it is not so viscous as to form a coating of undesirable thickness.

It will be manifest that other means than that of heat control may be provided for regulating the viscosity or fluidity without departing from the spirit and scope of the invention, it only being necessary that this viscosity be so controlled as to form the filmwithout appreciable permeation or saturation of the body receiving i. After the coating has been applied the containers are removed from the bath and the coating set by drying at like or lower temperatures in order that the film produced in the bath may not be destroyed.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing without further.

the process hereinbefore described being merely a present preferred embodiment thereof. T

I claim: v

1. The recess of proofing paper container bod-ies, which consists in providin a suitable rease repelling coating materia in fluid and viscous state, said coating being capable of being hardened by. drying, maintaining by heat the fluidity of said coating at a viscosit which will restrain absorption by the capi lary action of the material of the body of said container, applying said coating directly on the surface only of a fibrous container body and hardening the coating thus formed on said container body whereby said coatin is in the form of a continuous surface fifin 2. The rocess of proofing fibrous container bodies which consists in immersing a container in a grease-repelling coating material capable of variable viscosity at different temperatures, and maintained at a temperature which will give only suflicient viscosity to coat the surface of said con taine r but restraining thepermeatin of the container b capillary action, an subsequently drying and hardening said coating,

4. heprocess of proofing container bodies which consists in applying hide glue directly to a fibrous container bod under a temperature of about 110F. w ich will maintain the coating in a sufficiently viscous state to restrain permeation of t e body,

. and subsequently drying at like or lower tem erature.

Slgned 1n the presence of two subscribing witnesses.

FREDERICK P. WOOD. Witnesses:

J. C. CARPENTER, ESTHER ABRAMS.

glue to fibrous container bodies at a. 

